Tin Oxide with Controlled Morphology and Crystallinity by Atomic Layer Deposition onto Graphene Nanosheets for Enhanced Lithium Storage

Abstract

As one of the most promising negative electrode materials in lithium‐ion batteries (LIBs), SnO2 experiences intense investigation due to its high specific capacity and energy density, relative to conventional graphite anodes. In this study, for the first time, atomic layer deposition (ALD) is used to deposit SnO2, containing both amorphous and crystalline phases, onto graphene nanosheets (GNS) as anodes for LIBs. The resultant SnO2‐graphene nanocomposites exhibit a sandwich structure, and, when cycled against a lithium counter electrode, demonstrate a promising electrochemical performance. It is demonstrated that the introduction of GNS into the nanocomposites is beneficial for the anodes by increasing their electrical conductivity and releasing strain energy: thus, the nanocomposite electrode materials maintain a high electrical conductivity and flexibility. It is found that the amorphous SnO2‐GNS is more effective than the crystalline SnO2‐GNS in overcoming electrochemical and mechanical degradation; this observation is consistent with the intrinsically isotropic nature of the amorphous SnO2, which can mitigate the large volume changes associated with charge/discharge processes. It is observed that after 150 charge/discharge cycles, 793 mA h g−1 is achieved. Moreover, a higher coulombic efficiency is obtained for the amorphous SnO2‐GNS composite anode. This study provides an approach to fabricate novel anode materials and clarifies the influence of SnO2 phases on the electrochemical performance of LIBs.

How to improve the stability and rate performance of lithium-ion batteries with transition metal oxide anodes

“…[52][53][54] In this experiment, the attachment was completed before the annealing which induce the conversion of CoO precursor nanowires and GO sheets to rGO. The procedure is obviously effective to enhance the adhesion force between CoO nanowire and rGO.…”

One-Pot Hydrothermal Synthesis of Flower-Like SnO2Clusters and Their Application for Lithium Ion Battery

“…Fig. 3A shows the first three cyclic voltammograms of the SnO 2 -2 electrode conducted at a scan rate of 0.2 mV s In the first cycle, the CV curve clearly indicates a cathodic peak at 0.76 V during the first discharge, which can be attributed to the reduction of SnO 2 to Sn and the formation of solid-electrolyte interface(SEI) [20]. And the clear cathodic peak located at around 0.04 V can be attributed to the alloying reaction between Sn and Li to form LixSn alloy [21].During the charging process,two oxidation peaks ataround 0.62 and 1.25 V can be attributed to the dealloying ofLixSn, and the partial conversion of Sn to SnO 2 , respectively.The peak positions and intensitiesof all the redox couples echo well from 2nd to 3rd cycle,indicating the good reversibility of the electrochemical reactions.…”

Amorphous Iron Oxyhydroxide Nanosheets: Synthesis, Li Storage, and Conversion Reaction Kinetics

“…16 The AIO electrode demonstrates higher capacities than crystalline iron oxyhydroxide at the same current densities. 11,14,17 Some of the research reports proposed that the improved rate capability of amorphous electrode material results from higher lithium ion mobility in its loose structure and large quantities of structural defects. 6,18 However, for conversion-reaction type electrode materials, conversionreaction kinetics plays a more determinative role in electrode rate capabilities than Li + diffusion does.…”